#include <unistd.h>
#include <iostream>

using std::cout;
using std::endl;
using std::cerr;

int test0()
{
    //printf("hello,world\n");
    cout << "hello,world";
    //cout << "------" << endl;
    sleep(2);

    return 0;
}

void test1()
{
    for(int i = 0; i < 1025; ++i) {
        cout << 'a';
    }

    sleep(2);
    cout << "bbb" << endl;
}

void test2()
{
    cerr <<  "1";//立刻刷新，打印在屏幕,没有等待的时间
    sleep(2);
    cerr << "2";
}

int main() 
{
    /* test1(); */
    test2();
    return 0;
}
